Mitchell Wolf, 58, was taken into custody at 7:30 a.m. at a home on Bourne Lane in unincorporated Danville, according to police. Wolf is a math teacher at Diablo Vista Middle School in Danville, where he has taught since 2002.

The case was first brought by the Silicon Valley Internet Crimes Against Children Task Force and is now being investigated by the Danville Police Department and the Contra Costa Sheriff’s Office. Authorities said they were investigating whether there were any local victims.

Wolf has been put on administrative leave, effective Friday.

District officials said they did not believe any current or past students were involved, but expressed shock at the allegations.

“We are deeply saddened and shocked and are fully cooperating with the investigation,” said Terry Koehne, a district spokesman.

Wolf was booked at County Jail in Martinez on suspicion of possession of child pornography, and is being held on $1 million bail.